I wonder whther the first option A) could not trigger update triggers even when FieldA<>1301; or even an update IO. I mean, will the engine know that update set FieldA=FieldA would be a NOP?
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pascalJan 24 '11 at 13:01

I think that server performs IO operations in this case, but it is a fast inplace update.
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kolchanovJan 24 '11 at 17:38